I'm also experimenting with modifying some M&P mags and CZ mags to work with during the carbine. You must Reduce the notch inside the front from the mag so it'll lock in. I do not have any Glocks. Not bad, but thinking about the amount of factory mags are likely https://rugershotguns35566.thelateblog.com/32674245/ruger-shotguns-an-overview